/*!
 * jQCloud Plugin for jQuery
 *
 * Version 1.0.4
 *
 * Copyright 2011, Luca Ongaro
 * Licensed under the MIT license.
 *
 * Date: 2013-05-09 18:54:22 +0200
*/

(function( $ ) { 
    "use strict";
    $.fn.jQCloud = function(word_array, options) {
        // Reference to the container element
        var $this = this;
        // Namespace word ids to avoid collisions between multiple clouds
        var cloud_namespace = $this.attr('id') || Math.floor((Math.random()*1000000)).toString(36);

        // Default options value
        var default_options = {
            width: $this.width(),
            height: $this.height(),
            center: {
              x: ((options && options.width) ? options.width : $this.width()) / 2.0,
              y: ((options && options.height) ? options.height : $this.height()) / 2.0
            },
            delayedMode: word_array.length > 50,
            shape: false, // It defaults to elliptic shape
            encodeURI: true,
            removeOverflowing: true
        };

        options = $.extend(default_options, options || {});

        // Add the "jqcloud" class to the container for easy CSS styling, set container width/height
        $this.addClass("jqcloud").width(options.width).height(options.height);

        // Container's CSS position cannot be 'static'
        if ($this.css("position") === "static") {
            $this.css("position", "relative");
        }

        var drawWordCloud = function() {
            // Helper function to test if an element overlaps others
            var hitTest = function(elem, other_elems) {
                // Pairwise overlap detection
                var overlapping = function(a, b) {
                    if (Math.abs(2.0*a.offsetLeft + a.offsetWidth - 2.0*b.offsetLeft - b.offsetWidth) < a.offsetWidth + b.offsetWidth) {
                        if (Math.abs(2.0*a.offsetTop + a.offsetHeight - 2.0*b.offsetTop - b.offsetHeight) < a.offsetHeight + b.offsetHeight) {
                            return true;
                        }
                    }
                    return false;
                };
                var i = 0;
                // Check elements for overlap one by one, stop and return false as soon as an overlap is found
                for(i = 0; i < other_elems.length; i++) {
                    if (overlapping(elem, other_elems[i])) {
                        return true;
                    }
                }
                return false;
            };

            // Make sure every weight is a number before sorting
            for (var i = 0; i < word_array.length; i++) {
                word_array[i].weight = parseFloat(word_array[i].weight, 10);
            }

            // Sort word_array from the word with the highest weight to the one with the lowest
            word_array.sort(function(a, b) { 
                if (a.weight < b.weight) {
                    return 1;
                } else if (a.weight > b.weight) {
                    return -1;
                } else {
                    return 0;
                } 
            });

            var step = (options.shape === "rectangular") ? 18.0 : 2.0,
                already_placed_words = [],
                aspect_ratio = options.width / options.height;

            // Function to draw a word, by moving it in spiral until it finds a suitable empty place. This will be iterated on each word.
            var drawOneWord = function(index, word) {
                // Define the ID attribute of the span that will wrap the word, and the associated jQuery selector string
                var word_id = cloud_namespace + "_word_" + index,
                word_selector = "#" + word_id,
                angle = 6.28 * Math.random(),
                radius = 0.0,

                // Only used if option.shape == 'rectangular'
                steps_in_direction = 0.0,
                quarter_turns = 0.0,

                weight = 5,
                custom_class = "",
                inner_html = "",
                word_span;

                // Extend word html options with defaults
                word.html = $.extend(word.html, {id: word_id});

                // If custom class was specified, put them into a variable and remove it from html attrs, to avoid overwriting classes set by jQCloud
                if (word.html && word.html["class"]) {
                    custom_class = word.html["class"];
                    delete word.html["class"];
                }

                // Check if min(weight) > max(weight) otherwise use default
                if (word_array[0].weight > word_array[word_array.length - 1].weight) {
                    // Linearly map the original weight to a discrete scale from 1 to 10
                    weight = Math.round((word.weight - word_array[word_array.length - 1].weight) /
                                      (word_array[0].weight - word_array[word_array.length - 1].weight) * 9.0) + 1;
                }
                word_span = $('<span>').attr(word.html).addClass('w' + weight + " " + custom_class);

                // Append link if word.url attribute was set
                if (word.link) {
                    // If link is a string, then use it as the link href
                    if (typeof word.link === "string") {
                        word.link = {href: word.link};
                    }

                    // Extend link html options with defaults
                    if ( options.encodeURI ) {
                        word.link = $.extend(word.link, { href: encodeURI(word.link.href).replace(/'/g, "%27") });
                    }

                    inner_html = $('<a>').attr(word.link).text(word.text);
                } else {
                    inner_html = word.text;
                }
                word_span.append(inner_html);

                // Bind handlers to words
                if (!!word.handlers) {
                    for (var prop in word.handlers) {
                        if (word.handlers.hasOwnProperty(prop) && typeof word.handlers[prop] === 'function') {
                            $(word_span).bind(prop, word.handlers[prop]);
                        }
                    }
                }

                $this.append(word_span);

                var width = word_span.width(),
                height = word_span.height(),
                left = options.center.x - width / 2.0,
                top = options.center.y - height / 2.0;

                // Save a reference to the style property, for better performance
                var word_style = word_span[0].style;
                word_style.position = "absolute";
                word_style.left = left + "px";
                word_style.top = top + "px";

                while(hitTest(word_span[0], already_placed_words)) {
                    // option shape is 'rectangular' so move the word in a rectangular spiral
                    if (options.shape === "rectangular") {
                        steps_in_direction++;
                        if (steps_in_direction * step > (1 + Math.floor(quarter_turns / 2.0)) * step * ((quarter_turns % 4 % 2) === 0 ? 1 : aspect_ratio)) {
                            steps_in_direction = 0.0;
                            quarter_turns++;
                        }
                        switch(quarter_turns % 4) {
                            case 1:
                                left += step * aspect_ratio + Math.random() * 2.0;
                                break;
                            case 2:
                                top -= step + Math.random() * 2.0;
                                break;
                            case 3:
                                left -= step * aspect_ratio + Math.random() * 2.0;
                                break;
                            case 0:
                                top += step + Math.random() * 2.0;
                                break;
                        }
                    } else { // Default settings: elliptic spiral shape
                        radius += step;
                        angle += (index % 2 === 0 ? 1 : -1)*step;

                        left = options.center.x - (width / 2.0) + (radius*Math.cos(angle)) * aspect_ratio;
                        top = options.center.y + radius*Math.sin(angle) - (height / 2.0);
                    }
                    word_style.left = left + "px";
                    word_style.top = top + "px";
                }

                // Don't render word if part of it would be outside the container
                if (options.removeOverflowing && (left < 0 || top < 0 || (left + width) > options.width || (top + height) > options.height)) {
                    word_span.remove()
                    return;
                }


                already_placed_words.push(word_span[0]);

                // Invoke callback if existing
                if ($.isFunction(word.afterWordRender)) {
                    word.afterWordRender.call(word_span);
                }
            };

            var drawOneWordDelayed = function(index) {
                index = index || 0;
                if (!$this.is(':visible')) { // if not visible then do not attempt to draw
                    setTimeout(function(){drawOneWordDelayed(index);},10);
                    return;
                }
                if (index < word_array.length) {
                    drawOneWord(index, word_array[index]);
                    setTimeout(function(){drawOneWordDelayed(index + 1);}, 10);
                } else {
                    if ($.isFunction(options.afterCloudRender)) {
                        options.afterCloudRender.call($this);
                    }
                }
          };

          // Iterate drawOneWord on every word. The way the iteration is done depends on the drawing mode (delayedMode is true or false)
          if (options.delayedMode){
              drawOneWordDelayed();
          }
          else {
              $.each(word_array, drawOneWord);
                if ($.isFunction(options.afterCloudRender)) {
                    options.afterCloudRender.call($this);
                }
            }
        };

        // Delay execution so that the browser can render the page before the computatively intensive word cloud drawing
        setTimeout(function(){drawWordCloud();}, 10);
        return $this;
    };
})(jQuery);
